Fabbrizzi Luigi, Foti Francesco, Licchelli Maurizio, Maccarini Paola M, Sacchi Donatella, Zema Michele
Dipartimento di Chimica Generale, Università di Pavia, via Taramelli12, Italy.
Chemistry. 2002 Nov 4;8(21):4965-72. doi: 10.1002/1521-3765(20021104)8:21<4965::AID-CHEM4965>3.0.CO;2-X.
A cyclam-like macrocycle has been synthesized with a pendant arm containing a dansylamide group. In the corresponding nickel(II) complex, binding of the pendant arm to the metal is pH controlled. In particular, at pH 4.3, the sulfonamide group deprotonates and coordinates the NiII center, giving rise to a complex of trigonal bipyramidal stereochemistry, as shown by X-ray diffraction studies performed on the crystalline complex salt. At pH 7.5, an OH- ion binds the metal and a six-coordinate species forms. The binding-detachment of the pendant arm to/from the NiII center is signaled by changes in the emission properties of the dansyl subunit in the side chain; the fluorescence of this side chain is high when the pendant arm is not coordinated and low when the sulfonamide group is bound to the metal. The system investigated represents the prototype of a light-emitting molecular machine, driven by a pH change.
已合成了一种类似环戊二烯的大环化合物，其带有一个含有丹磺酰胺基团的侧链臂。在相应的镍（II）配合物中，侧链臂与金属的结合受pH值控制。特别是在pH 4.3时，磺酰胺基团去质子化并与NiII中心配位，形成具有三角双锥立体化学结构的配合物，这通过对结晶配合物盐进行的X射线衍射研究得以证实。在pH 7.5时，一个OH-离子与金属结合，形成六配位物种。侧链臂与NiII中心的结合-解离通过侧链中丹磺酰亚基发射特性的变化来指示；当侧链臂未配位时，该侧链的荧光较高，而当磺酰胺基团与金属结合时，荧光较低。所研究系统代表了一种由pH变化驱动的发光分子机器的原型。
